The present invention relates to the field of mass storage devices. More particularly, this invention relates to a compliant clamping mechanism for accurate alignment of a group of miniature parts, such as processing of bars of a strip of heads for a disc drive.
One key component of any computer system is a device to store data. Computer systems have many different places where data can be stored. One common place for storing massive amounts of data in a computer system is on a disc drive. The most basic parts of a disc drive are a disc for storing data. The disc includes a magnetic layer. A transducer is passed over the surface of the disc and is used to either magnetize the magnetic layer of the disc or to detect magnetized portions of the disc. The transducer is typically housed within a small ceramic block known as a slider. The transducer is attached to an actuator. The actuator moves the slider and the transducer within the slider to various locations over the disc where information representing data is written to or retrieved from the disc surface.
The process of forming individual sliders starts with forming multiple transducers on a surface of a ceramic wafer using semiconductor fabrication techniques. After forming the transducers on the wafer, the wafer is then sliced or cut to form an elongated bar having a row of transducers (a rowbar). The rowbars are elongated pieces of ceramic that are fragile. The rowbars undergo many manufacturing processes and must be held firmly. The holder for the rowbars must be able to accommodate slight variations in dimension and hold the rowbar firmly throughout these various processing steps. The processing steps include various steps for removing material including lapping to provide a first xe2x80x9crough approximationxe2x80x9d removal of material and milling for removing material at a slower, more controlled rate than the lapping process. An air-bearing surface is also formed on the rowbars before being diced into individual sliders.
In the past, mechanical clamping fixtures for holding small, fragile parts have been designed to hold single parts. Some clamping fixtures hold multiple small parts but generally these clamps have several problems. One rather large problem associated with clamps for holding multiple parts is that not all the parts are adequately secured due to variations in individual part dimensions. A clamping mechanism for holding small parts has limited space. Due to the limited space, there is little room for fitting a complicated apparatus to securely hold multiple small parts. Furthermore, even if a complicated apparatus can securely hold multiple parts, the more complicated an apparatus is the more difficult the apparatus is to use. Complicated apparatus are also generally more time consuming and costly to produce.
As a result, there is a need for a simple clamp that produces an appropriate amount of force to hold multiple small parts. Clamping multiple parts simultaneously is particularly difficult due to variations in individual part dimensions. Thus, there is also a need for a compliant clamping structure that is capable of accommodating size differences in several small or miniature parts and that is self-adjusting so that these parts may be continued to be held as they undergo multiple processing steps. There is also a need for a spring structure that can hold small parts reliably without yielding or plastically deforming. The clamping mechanism must also be capable of enduring the environments associated with the processes that the small or miniature parts undergo during manufacture. Due to their small and varying size, very small or miniature parts are difficult to hold in place for further processing, particularly, when multiple miniature parts need to be held in a limited space. In summary, there is a need for a clamping mechanism that simultaneously secures multiple miniature parts in a limited space that has a reduced cost.
A clamping apparatus for holding elements includes a first spring member and a second spring member. The first spring member has a rigid portion that applies the majority of force to the elements. The second spring member is attached to the first spring member. The second spring member is more flexible than the first spring member. The second spring member has a structure that accommodates dimensional variations in elements held by the clamping member.
A clamping apparatus for holding elements includes a first spring member. The first spring member includes a rigid portion that applies the majority of force to the elements. The clamping apparatus includes a second spring member. The second spring member is attached to the first spring member. The second spring member is more flexible than the first spring member. The second spring member accommodates dimensional variations in the elements held by the clamping member. The second spring member includes a plurality of flexible structures for holding elements. The first spring element surrounds the second spring member. The first spring element has a notch therein. The first spring element has an opening for handling the spring. The first spring element has at least one slit therein. The dimension of the at least one slit determines the spring force produced by the first spring element. The first spring element may also have a plurality of slits therein. In this case, the plurality of slits determine the spring force produced by the first spring element.
The first spring element is rectangular. The second spring element is attached to one side of the rectangle of the first spring element. The second spring element includes a plurality of elongated openings for holding a plurality of elongated elements. The second spring element includes a plurality of elongated bars for contacting a plurality of elements. The second spring element may include a plurality of elongated bars for contacting a plurality of elements. At least one of the elongated bars includes a rounded feature or at least two rounded features for contacting an element.
A method for clamping elements includes the steps of holding at least one element with at least one flexible bar, and attaching the flexible bar to a rigid frame. The one flexible bar and a portion of the rigid frame hold the element. The rigid frame produces a majority of the force for holding the at least one element. The flexible bar is dimensioned to accommodate variations in dimensions associated with the one element. One or more slits may be placed in the rigid frame to adjust the amount of force applied to clamp the element. A second flexible bar may be added to hold a second element. The second flexible bar is spaced away from the first flexible bar so as to accommodate the dimension of a second element. The first flexible bar contacts a first element on one side and a second element on the other side.